In a saucepan over medium heat, combine fresh blueberries, sugar, and lemon juice. Cook until the blueberries soften, about 5-7 minutes. Mix cornstarch with water to create a slurry, add it to the saucepan, and cook until thickened, about 2-3 minutes. Strain the sauce and let it cool.

Preheat your oven to 325°F (160°C) and line a muffin pan with cupcake liners.

In a mixing bowl, combine graham cracker crumbs, sugar, and melted butter until it resembles wet sand. Press into the bottom of each cupcake liner. Bake for about 5 minutes or until golden. Let cool.

In a stand mixer, beat cream cheese and sugar until smooth. Add lemon juice, zest, and vanilla, mixing until combined. Gradually add eggs while mixing on low. Avoid overmixing.

Spoon cheesecake filling into cooled crusts, filling each about three-quarters full. Gently swirl in blueberry sauce.

Bake for 17-20 minutes, until slightly set with a gentle jiggle. Allow to cool for about 1 hour.

Transfer to the refrigerator and chill for at least 3-4 hours.